Device for determining the position of a body to be positioned with respect to a reference body

• US 5,648,851 A
• Filed: 09/14/1995
• Issued: 07/15/1997
• Est. Priority Date: 03/17/1993
• Status: Expired due to Fees

• Current Assignee: EMS Technik GmbH
• Original Assignee: EMS Technik GmbH
• Inventors: Kellner, Helmut
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US08/522,347
• Time in Patent Office: 670 Days
• Field of Search: 356/373, 356/374, 356/375, 250/237, 33/707
• US Class Current: 356/616
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01D 5/262 with optical projection of a pointer or a scale

Abstract

A device is disclosed for determining the position of a body to be positioned with respect to a reference body. The body to be positioned carries a graduation with optical detectors. The coordinates of a projection center are trigonometrically calculated from the projection angles formed between the projection center and at least three light marks projected onto the graduation, as well as from the distance between the light marks. The projection center is formed by the common intersection point between the optical axes or by the common intersection line between the optical planes of at least three diverging and/or converging projectors arranged on the reference body and which emit light beams or light planes. The light marks projected onto the graduation are detected by the optical detectors.

Claims

1. A device for determining the position of a body to be positioned relative to a reference body, comprising:

a body bearing a graduated scale including optical samplers;

a reference body including at least three projectors which form projection angles to one another and the optical axes of which form at least one projection center, said at least three projectors projecting at least three projected light marks on said graduated scale of said body; and

means for trigonometrically calculating the coordinates of said at least one projection center from the projection angles between said at least one projection center and at least three projected light marks as well as from a spacing distance between said at least three projected light marks as acquired by said optical samplers.

2. A device as claimed in claim 1, wherein said at least three projectors emit one of light beams and light planes.

3. A device as claimed in claim 1, wherein said at least three projectors each include a laser light source with a lens and a diaphragm.

4. A device as claimed in claim 1, wherein said at least three projectors include a common laser light source with a light distribution lens and diaphragms.

5. A device as claimed in claim 4, wherein said diaphragms include at least one of apertured diaphragms for producing light beams and slit diaphragm for producing light planes.

6. A device as claimed in claim 3, wherein said diaphragm includes at least one of an apertured diaphragm for producing light beams and a slit diaphragm for producing light planes.

7. A device as claimed in claim 1, wherein said optical samplers include a CCD line.

8. A device as claimed in claim 2, wherein said optical samplers include a CCD line.

9. A device as claimed in claim 1, wherein said optical samplers are connected with said calculating means which determines the mean maximum of a projected light mark from the brightness distribution of a projected light mark falling on several optical samplers and allocates this to the optical axis.

10. A device as claimed in claim 2, wherein said optical samplers are connected with said calculating means which determines the mean maximum of a projected light mark from the brightness distribution of a projected light mark falling on several optical samplers and allocates this to the optical axis.

11. A device as claimed in claim 1, wherein said at least one projection center is a single projection center which lies on a side of said graduated scale facing the projectors where the optical axes of the projectors diverge, and is a single projection center which lies on a side of the graduated scale facing away from the projectors where the optical axes of the projectors converge.

12. A device as claimed in claim 1, wherein said calculating means is connected with the optical samplers and calculates coordinates of said at least one projection center according to the following trigonometric functions and equations:

##EQU6## whereby, α

refers to the projection angle between the projection center as well as a first and a second optical axis, β

refers to the projection angle between the projection center as well as a second and a third optical axis, X₁, X₂, X₃ refer to individual samplers onto which said projected light marks impinge in a row of samplers, with X₂ as the intersection with the middle vertical of the reference body, and d₁ and d₂ refer to the means distances between the samplers X₂ and X₁ or X₃ and X₁.

13. A device as claimed in claim 12, wherein said calculating means also calculates the slope angle f of the body to be positioned in relation to the reference body trigonometrically according to the functions and equations:

##EQU7## whereby d₃ is the distance between the intersecting point X₀ of the plumb of said at least one projection center to the graduated scale and the intersecting point X₂ of the center perpendicular line to the reference body with the graduated scale.

14. A device as claimed in claim 2, wherein said calculating means is connected with the optical samplers and calculates coordinates of said at least one projection center according to the following trigonometric functions and equations:

##EQU8## whereby, α

refers to the projection angle between the projection center as well as a first and a second optical axis, β

refers to the projection angle between the projection center as well as a second and a third optical axis, X₁, X₂, X₃ refer to individual samplers onto which said projected light marks impinge in a row of samplers, with X₂ as the intersection with the middle vertical of the reference body, and d₁ and d₂ refer to the means distances between the samplers X₂ and X₁ or X₃ and X₁.

15. A device as claimed in claim 14, wherein said calculating means also calculates the slope angle f of the body to be positioned in relation to the reference body trigonometrically according to the functions and equations:

##EQU9## whereby d₃ is the distance between the intersecting point X₀ of the plumb of said at least one projection center to the graduated scale and the intersecting point X₂ of the center perpendicular line to the reference body with the graduated scale.

16. A device as claimed in claim 1, wherein on said body two parallel graduated scale portions lie in one plane and two projector arrangements are arranged on the reference body and each made of said at least three projectors and are each allocated to a respective graduated scale.

17. A device as claimed in claim 2, wherein on said body two parallel graduated scale portions lie in one plane and two projector arrangements are arranged on the reference body and each made of said at least three projectors and are each allocated to a respective graduated scale.

18. A device as claimed in claim 1, wherein on the body two graduated scale portions are arranged at an angle of about 90°

and two projector arrangements are arranged on the reference body and each made of at least three projectors respectively allocated to each graduated scale portion.

19. A device as claimed in claim 2, wherein on the body two graduated scale portions are arranged at an angle of about 90°

and two projector arrangements are arranged on the reference body and each made of at least three projectors respectively allocated to each graduated scale portion.

20. A device as claimed in claim 1, wherein on the body three graduated scale portions are arranged, of which two lie in one plane and a third is oriented at an angle of 90°

to both the other graduated scales and three projector arrangements are arranged on said reference body and each are made of at least three projectors allocated to respective graduated scale portions.

21. A device as claimed in claim 2, wherein on the body three graduated scale portions are arranged, of which two lie in one plane and a third is oriented at an angle of 90°

to both the other graduated scales and three projector arrangements are arranged on said reference body and each are made of at least three projectors allocated to respective graduated scale portions.